Creating connected objects (block or group) and limit manipulation to my commands only


I need to create “custom” object from one planar closed curve. It is fabric panel and I have to add seams and overlaps.

So what would be the best way to do it as block or group or something else? Can I limit manipulation of such object to just my commands (scripts).

What is usual place to store extra information for this object SetUserText or?

Can this be done in python or it should be done with C++ plugin?